Implantable Muscle Closing Prosthesis System, in Particular in the Anal Channel Area

ABSTRACT

An implantable muscle closing prosthesis system, particularly for opening and closing the rectum, characterized in that it has a compression unit, which comprises a compression cuff ( 1 ) and a reservoir cuff ( 2 ) molded as hollow bodies, and may integrate a bidirectional micropump ( 4 ) of arbitrary construction via a support ring ( 3 ), the cast primarily being subjected to a material compression during the inflation and deflation and communicating with one another via the micropump ( 4 ), which may be activated using a separate control unit, or is also manually operable from the outside.

The present invention relates to an improved, implantable sphincter prosthesis system for treatment of high-grade stool incontinence, which may be implanted in a space-saving way around the anal channel due to its highly integrated conception.

The currently clinically relevant Acticon Neosphincter, which is described in the literature, for treating high-grade stool incontinence comprises three separate functional components to be implanted in different anatomical areas: an inflatable ring to be adjusted around the intestine like a collar, which compresses the anal channel, a separate pressure accumulator for the compression medium, and a unidirectional pump, which connects the two components and pumps the compression medium out of the compression collar back into the pressure accumulator (Wong W D, et al., Disease of Colon and Rectum 2002, 9:1139-1153). The configuration of the functional components requires complex surgery and results in complication and explantation rates around 40%. A more compact muscle closing device, in which a change of the viscosity and density of a colloidal magnetorheological liquid is exploited for the compression procedure (U.S. Pat. No. 5,509,888 A), is without clinical relevance up to this point and does not correspond to the features of the characterizing part in claim 1. Various devices comprising multiple seal elements which move peristaltically for closing an end of the intestine (DE 100 23 634 C2; DE 197 32 92 A1) are not usable in the area of the anal channel and thus differ significantly from the present invention described in claim 1, as do the systems for closing the urethra (DE 90 10 783 U1; EP 02 02 815 A2; EP 03 48 114 A1) known from urology.

Furthermore, the compression collars described in the literature are highly elastic inflatable bodies, which are essentially subject to an expansion in the scope of the inflation or deflation (balloon principle). Achieving a circular, symmetrical, and efficient lumen compression using extremely small volumes against high pressures, as may occur in the scope of efficient continence compression in the area of the anal channel, is subjected to narrow limits because of the strong deformation of the inflatable bodies. In addition, the high pressure gradient already existing at the beginning in the inflatable bodies influences the performance spectrum of a micropump which is employed extremely negatively during the inflation.

The innovation thus relates to a muscle closing prosthesis for voluntarily achieving stool continence or defecation, which, because of its unique compact construction and function may be implanted in a significantly simplified way perianally, over the sphincter ani extemus muscle in the area of the anal channel, or conventionally, using laparotomy or laparoscopy at the level of the inferior pelvic aperture, and integrates all components necessary for its function.

This object is achieved according to the present invention by the structure of a compression unit which comprises four elements according to claim 1: a special compression cuff (1) formed as a hollow body on the interior of an elastic support ring (3), on whose exterior the reservoir cuff (2) for the compression medium is located. Compression cuff (1) and reservoir cuff (2) communicate via a bidirectional micropump (4) of arbitrary construction (based on piezo technology, for example) which is integrated in the support ring (3) or attached thereto, and via transmission lines (6) which are completely or partially integrated in the ring.

All surfaces comprise one or a combination of multiple different biocompatible and/or physiologically inert materials (such as polyurethane, titanium) isotonic sodium chloride solution or oils compatible with the body being able to be used as transmission fluids or a gas or gas mixture, e.g., air, being able to be used as transmission media.

The function and further advantages of the muscle closing prosthesis are explained by the embodiment description on the basis of FIG. 1.

REFERENCE NUMERALS

-   1 compression cuff -   2 reservoir cuff -   3 support ring -   4 micropump -   4 a/b shutoff valves -   5 pressure sensor -   6 transmission line -   7 quick-acting closure -   8 port -   9 terminal for external power source/control electronics

In detail, FIG. 1 shows the complete compression unit in coronary section, having compression cuff (1) and reservoir cuff (2), the support ring (3), and the integrated micropump (4). The molded hollow bodies of the compression and reservoir cuffs are shown in a non-evacuated, or inflated state. The compression cuff (1) is shown in a concave, three-chamber embodiment.

The use of a bidirectional micropump (4) having integrated shutoff valves (4 a/b), implemented in FIG. 1 as a piezo pump, allows the reduction of the large pressure equalization or reservoir container to be implanted separately, which was typical until now. The volume solely has to correspond to the compression volume in this way, so that the reservoir cuff (2) may be attached to the exterior of the support ring (3).

A further innovation according to claim 1 is the embodiment of the compression cuff (1) and reservoir cuff (2), which are manufactured as hollow bodies, which may be evacuated, made of polyurethane, for example, which is outstandingly suitable for this purpose. The inflation or deflation is based primarily on a material compression and deformation of a hollow body having defined volume at largely constant wall thickness and not on a material expansion, as is normal in the typical compression bodies manufactured from silicone, for example.

In addition to the lower material strain, the advantage is the elimination of the initial expansion resistance of the compression cuff (1), from which a hysteresis phenomenon of the intra-cuff pressure during the compression filling is derived. This constellation, in combination with the minimal dead space volume of the transmission lines (6) resulting from the integrated system conception, has a positive effect on the performance characteristic and the energy management of the micropump (4) to be used.

The support ring (3), and the cuffs (1, 2) attached on both sides (ideally manufactured from polyurethane), allow the opening of the ring for implantation by 180°. The ring may be mechanically or electromagnetically closed by a quick-acting closure (7).

After implantation of the prosthesis having primary evacuated cuffs, the reservoir cuff (2) is filled via the port (8). The activation of the micropump (4) causes the filling of the compression cuff (1) from the reservoir cuff (2) via the integrated transmission lines (6). The closure of the anal channel is produced (continence performance).

A reversal of the fluid or air transmission causes the emptying of the compression cuff (1) (defecation). The integrated pressure sensor (5) allows a tissue-protective pressure regulation and is additionally usable as an indicator for an imminent defecation (increase of the intra-cuff pressure in the event of waiting stool column). A separate patient programming unit is used for voluntary activation of the continence performance or defecation (function on/off, or pressure/volume adapted regulation as a function of the stool consistency and within a pressure range predefined by the physician). In this case, a subcutaneously implanted receiver is activated telemetrically or by radio, for example, using the patient programming unit, the receiver being connected via a cable connection by suitable terminals (9) to the sphincter prosthesis. The activation may also be performed using a radio remote-control module integrated in the prosthesis, through which the functional components are reduced by the subcutaneous receiver and the cable connection. 

1. An implantable muscle closing prosthesis system for opening and closing the anal channel or a hollow organ segment, characterized in that an elastic compression cuff, which may be evacuated and is molded as a hollow body, on the interior of an elastic support ring is connected via an integrated or nonintegrated micropump of arbitrary construction to an elastic reservoir cuff, which may also be evacuated and is also molded as a hollow body, attached to the exterior of the support ring, the transmission fluid or a gas or gas mixture being injectable into the reservoir cuff, which is evacuated, via a port and being transferred via the micropump between evacuated reservoir cuff and compression cuff and the micropump being able to be activated magnetically, telemetrically, or by induction coil by an external programming device via an interposed receiver to be implanted separately, which is connected to the prosthesis via a cable, for example, or directly by radio.
 2. The muscle closing prosthesis system according to claim 1, characterized in that the compression cuff provided as a molded hollow body on the interior of the support ring may be implemented having the surface facing toward the hollow organ to be compressed as convex or concave and comprising multiple individual chambers connected to one another, which may be filled simultaneously or in delayed chronological sequence, symmetrically or asymmetrically to one another, and thus compress the hollow organ circularly.
 3. The muscle closing prosthesis system according to claim 1, characterized in that the compression cuff provided as a molded hollow body on the interior of the support ring may be implemented having the surface facing toward the hollow organ to be compressed convex or concave and comprising multiple individual chambers connected to one another, which may be filled in such a way that the hollow organ may be compressed against a fixed, soft buttress, such as a gel cushion, by producing an angle (closure through buckling).
 4. The muscle closing prosthesis system according to claim 1, characterized in that elastic, compressible filler cushions, e.g., foam, may be introduced to reduce the compression volume inside the compression cuff molded as a hollow body.
 5. The muscle closing prosthesis system according to claim 1, characterized in that the reservoir cuff attached to the exterior of the support ring comprises one or more molded hollow chambers connected to one another.
 6. The muscle closing prosthesis system according to claim 1, characterized in that the reservoir cuff molded as a hollow body may be protected on all sides by a flexible envelope connected to the support ring, which is not directly connected to this hollow body, however, and thus may not be evacuated in the scope of the deflation of the hollow body and is thus used as a tissue expander.
 7. The muscle closing prosthesis system according to claim 1, characterized in that at least one or more valves for blocking the fluid and/or the gas or gas mixture transmission are situated between the compression cuff and the reservoir cuff and/or are integrated in the micropump because of its construction.
 8. The muscle closing prosthesis system according to claim 1, characterized in that the micropump does not have to be integrated directly in the prosthesis, but rather may be transferred into another anatomical space in arbitrary construction, bidirectionally or unidirectionally controlled or as a manual unidirectional pump, and in this case is connected via a transmission line to the compression cuff and reservoir cuff.
 9. The muscle closing prosthesis system according to claim 1, characterized in that with a unidirectional construction of the pump, the compression liquid and/or the gas or gas mixture is pumped actively from the reservoir cuff into the compression cuff and the compression cuff is emptied passively because of the existing pressure gradient between it and the evacuated reservoir cuff and because of the pressure which is exerted by the stool column on the compression cuff during the defecation. 